Wednesday, February 27, 2013

Growing key limes in north Florida (and probably beyond)

Yes - it can be done!

In a previous post or two on microclimates, I've mentioned that I grow zone 10 plants in my zone 8b yard.

One tree that has a deep allure for gardeners is the Key Lime. This tree has almost an almost shamanistic pull upon anyone from about Broward County down south to the Keys. It represents the tropics. Margaritas. Salt breezes.

And of course - the king of all citrus confections - Key Lime pie.

Basically, Key Limes =

The problem is: Key Limes can't stand freezing since they're one of the most tropical of all citrus. Up here, the poor trees will freeze to the ground ever year, then limp back with a foot or two of growth, only to get knocked down again. Growing them without protection is impossible - and growing them with protection is risky and time consuming. Can you really be at your house for every frost? Will you remember to wrap your viciously thorny Key Lime tree with Christmas lights and cover it with blankets? Will you watch the weather like a hawk all winter?

Like I said - it's time consuming... and I really don't want to bother.

Fortunately, I've found a way that works without all that trouble. I grow my Key Lime tree outside and unprotected and it's doing great.

Here it is this very February, after we've had close to ten freezes:

Cool, huh? The tree is completely and utterly unscathed, thanks to a tree-training method called "espaliering" and the almost mythically powerful south wall of my house.

To do it, I nailed those three pieces of galvanized conduit into the ground with a hammer and also secured them to the wall near their tops. The tree is planted within a foot of the wall, keeping it safely inside the warm pocket created by the concrete's thermal mass. As branches grow forwards, I tie them back to the conduit, keeping them from reaching out too far and into the Frost Zone of Death.

I'm sure there's a prettier way to pull this off - but I can't argue with the results. There's a lot of tender new growth right now that hasn't been touched in the slightest by cold.

You know... I think I might need to set a few conch shells down to match the coconuts (sadly, imported from south Florida) at the base of that tree.

When I first moved to north-central Florida, in my ignorance, I planted a few key lime seeds directly in the ground, in the most open, exposed area of the yard. It sprouted, grew to about 8", then died in the winter freeze, despite my attempts to shield it.

Then, in the summer, it sprouted again from the bottom, growing to over a foot before repeating its winter performance. It did the same for the following 4 years growing about 3-4" higher each time. Its final iteration has it up over 3" tall, and I'm waiting to see if it springs to life again after this past winter. So far, no fruit, but I am just curious to see how this story ends.

You can totally grow bananas there - it's just not as easy as it is down in the far south of the state. Try Raja Puri, finger bananas and "Ice Cream" bananas... all three are supposed to be more tolerant of the cold. My big problem is losing the blooms and young fruit to frost. It's hard to get bananas to fruit when you want them to.